I'm currently hospitalized, and today, they wanted me to take a drug test, as I've been home for a couple of days. I was more than happy to provide them with the urine sample they wanted, why wouldn't I, considering I'd already told them about the one joint I smoked a month ago, and haven't done any other drugs during the last six months exept for those prescribed by my M.D, Ritalin and Flunipam (Rohypnol), not exceeding the prescribed dose.

When they told me that I'd tested positive for both hash and metaamphetamine, I couldn't belive it- I expected them to find traces of hash, but as I'd told them about it already, and I took a urine test when I was admitted a week ago, I assumed they'd found hash in that test. Turns out they hadn't tested my urine for drugs, and now suspect me of smoking hash while I was home.

But what really shocked me was them finding traces of meth. The last time I did meth was at least 8 months ago. I don't understand how I could possibly test positive for it NOW?

I demanded a new test, preferably a blood test, but as the lab was closed for the day, a second urine test was the only option today. The second test was "unclear"- still traces of hash, but as for meth, the test did not provide a definitive result.

Can Ritalin be confused with meth in a drug test? If not, what can possibly have caused me to test positive for meth? I'm on 100 mg a day, if that matters.

When they do a blood test, which I will demand that they do, will it prove that I've not taken meth? Or can whatever caused the urine test to show traces of meth, also cause a positive result in a blood test? From what I've read, blood tests are more accurate and reliable, right?

I'm really anxious, as them suspecting me of abusing meth will have very serious consequenses, they're very strict when it comes to prescribing stimulants here in Norway, and even someone who have only abused drugs in the past, but been clean for years, will have trouble finding any medical professional willing to prescribe stimulants, nor will he get strong sleeping pills like the ones I'm on- and someone who is currently abusing drugs like meth will definitely not get a prescription for such drug- and at the moment, they suspect me for being that "someone".

Joker_Girl

11-25-09, 11:52 AM

I *THINK* Ritalin, Adderall, anything like that can cause a false positive, and if you have a script for this, that it would be excused. In fact, I am almost certain that it can cause a false positive, if that is all they are testing for.
Also, cold medicines containing Sudafed can cause that.

Fima

11-25-09, 12:19 PM

I hate drug tests!
I never done it, its not their buisness what drugs I am using(well, unless its an health problem, in wich I provide the information by my own).

as far as the story goes, its caused by Ritalin, Ritalin gets out of the body after 4 hours(IR), just don't use it when you do the drug test again.

Ethereal

11-25-09, 12:44 PM

As I'm hospitalized, avoiding taking Ritallin is a bit tricky, as they watch me take it-including checking that I haven't hidden the pills under my tongue. Also, if I don't take Ritalin, they would wonder why there's no trace of Ritalin in the test. Hopefully, the blood test will clear up this little "misunderstanding", as when I asked the nurses whether Ritalin may have caused me to test positive for meth, they claimed that it wasn't possible.

Kiddder

11-25-09, 02:28 PM

Here is a great reference site regarding substances that can result in false positive tests;

http://www.askdocweb.com/falsepositives.html

More than 250 over-the-counter or prescription drugs can cause you to test positive on a drug test.

Pain relievers such as Advil, Nuprin, Motrin
Menstrual cramp medications like Midol and Trendar
Ibuprofen is known to cause positive samples for Marijuana
Anti inflammatories such as Naproxyn
Dristan Nasal Spray, Neosynephren, Vicks Nasal Spray, Sudafed
Over the counter appetite suppressants which contain propanolamine
Common nasal decongestants can cause a positive reading for Amphetamines
Medications containing chloropromazine and fluspirilene may yield a positive when tested for amphetamines
Vicks Formula 44M containing Dextromethorphan, and Primatene-M containing perylamine as well as the pain reliever Demerol, and prescription anti-depressant Elavil test positive for opiates up to three days
Quinine water can also cause a positive reading for opiates.
Poppy Seeds such as the ones on a bagel from your favorite deli, represent a potentially serious source of falsely positive results in testing opiate abuse.
Nyquil Nighttime Cold Medicine will test positive for Methadone up to two days.
Amoxicillin has caused positives for cocaine
Diazepam tests positive for PCP
A small fraction of the population excrete large amounts of endogenons lysozyme or malate dehydrogenase in their urine which can produce a positive drug test.
Africans and certain Orientals might test positive for marijuana due to the pigment melanin in their skin which shows up in a dark person's urine sample.
Second hand marijuana or cocaine that you might inhale may give your test a positive result for several days.

Kiddder

11-25-09, 02:31 PM

What is a false positive? It is a test result that is returned when a substance tests positive for another compound. It is a case of mistaken identity. For example if you eat a couple poppy seed cakes before testing, you can get a positive result for opiates.

The chances of you getting a false positive depends on the quality of the laboratory that does the testing. There seems to be about 1,200 of these labs in the United States currently testing for drugs. Less than a 100 of these meet federal standards and most of the individual states do not regulate drug test labs. The number of false positives returned range from 4% to over 50%, depending on the lab.

PedroDaGr8

11-25-09, 04:36 PM

OK, since the person above me said that false positives are related to the training of the lab, I felt I should contribute some. As a chemist, this will be a bit technical but it applies to ANY test you have done (whether it be hospital blood tests, urine/blood drug tests, etc.).

There are three sources of error in any analytical test. The colloquial names are: systemic error, human error and random error. False positives AND false negatives can come from any three of these sources.

Systemic Error:
Systemic errors are errors inherent in the system itself. These are often times unavoidable errors such as responding to or being inhibited by similar compounds, detection limits, etc.

In the case of drug tests, systemic error related false positives would be compounds that mimic the response of illicit drugs in the testing media. False negatives would be compounds that inhibit the response of the testing media. The hallmark of systemic error is that it is repeatable. The system fed the same sample responds the same way every time.

Human Error:
Human errors are just like they sound, errors caused by the operator of the test. These can range from inappropriate standards, contamination of the sample, contamination of the system, etc. For example, say the tech smoked weed the night before and had residue on their hands. There is a VERY slight chance some of the residue could come off in a sample, if precautions are not taken (which since it is biological fluids 99% chance they ARE taken). In general though, human error tends to affect quantitative readings (the amounts) more than it does the qualitative (is it there or not). The only exception being where the reading falls below the detection limit.

Random Error:
This is the completely unexplainable errors and fluctuations that occur due to the chaotic nature of the system. For example, the minute fluctutations of concentration within a solution could make the system read higher or lower concetrations than the predicted average. Similarly, systems based on electricity, ie fluorescence detection, absorbance/emittance, etc. All will have values that flucuate slightly based on noise in the electrical supply. This is random error.

Now for drug tests:

I wouldn't claim to know which system they are using but two common ones are Gas Chromatography/Mass Spectrometry (GCMS) and Immunoassy.

The GCMS is the MUCH more complex of the two. Ideally, the way it works is that the GC part seperates the various compounds in the urine into different peaks/bands and these peaks are fed into a mass spectrometer. The mass spectrometer ionizes and fragments the various compounds resulting in a finger print like spectra. Now come the drawbacks to this system. In the LC section, similar compounds will elute (come out) at similar times, meaning their peaks/bands overlap. This causes noise in the MS because there are two fingerprints on top of each other, often resulting in an indefinite response. Additionally, a compound may elute at a time that is the exact same as a supposed drug. This is why LC by itself CAN NOT be used to test for drugs. Now in the MS side of things, the ionization methods used tend to be what are called HARSH ionization methods. This means that they fragment the compound. Harsh methods are used because in soft methods, the only information you would have is the M+ (Mass peak) and the time it eluted. No details on structure. Harsh methods are not without their downsides either. If care is not taken in how harsh the method is, you can actually completely LOSE the M+ peak. Now that may not seem like a big deal, but in the case of methyl phenidate, cleave that Methoxyketone (CH3OC=O) and four of the carbons off of the piperidine ring and guess what, you get something remarkably similar to methamphetamine.

Immunoassay is the much easier to run of the two, but it as well is not without its drawbacks. It is MUCH more likely to respond to similar chemicals. It is MUCH more likely to be blocked by similar chemicals, etc. Additionally, it occurs in two varieties. Colorimetric (produces a color change) and fluorescent. In general fluorescent gives much better quantitative yields and detection limits, but colorimetric doesn't require outside equipment. The immunoassay works by having each different region on a strip, piece of paper, silica column, etc. possess antigens (we will call A) for a different drug (we will call D). You are strictly limited to testing for drugs to which the test strip has antigens. A solution is flowed through the testing media and the antigens A bind and hold onto the drug molecule D. A solution containing a second antigen (we will call B), which has an affinity for the first antigen ONLY when it is bound to the drug molecule(A+D) is now run through the system. This second antigen also has a fluorescent or colorimetric tag bound to it. WHen it encounters one of the first antigens with a drug bound to it, the second antigen binds to that providing a signal (via its fluorescent or colorimetric tag). Any unbound second antigen that has not bound to anything is washed away. What is left is either free antigen A, no signal, or A+D+B which produces a signal. This system can have errors when washing is not done properly, when similar compound bind and are detected, etc. For example, an antigen for methamphetamine may bind similarly but much less strongly to ephedrine.

One large caveat, the above assumes they are looking for the pure drug. Many times they are not. Instead, they are looking for metabolites. As I don't know what metabolites of meth are present in urine, I can't say how similar the metabolites are. I will check and see though and post more in a minute.

Kiddder

11-25-09, 05:10 PM

What is a false positive? It is a test result that is returned when a substance tests positive for another compound. It is a case of mistaken identity. For example if you eat a couple poppy seed cakes before testing, you can get a positive result for opiates.

The chances of you getting a false positive depends on the quality of the laboratory that does the testing. There seems to be about 1,200 of these labs in the United States currently testing for drugs. Less than a 100 of these meet federal standards and most of the individual states do not regulate drug test labs. The number of false positives returned range from 4% to over 50%, depending on the lab.

"OK, since the person above me said that false positives are related to the training of the lab, I felt I should contribute some. As a chemist, this will be a bit technical but it applies to ANY test you have done (whether it be hospital blood tests, urine/blood drug tests, etc.)."

Thanks for a more qualified and experienced explanation on testing methods PedroDaGr8. Not to sound defensive, but to clarify I think my post stated "quality of lab" not training of personel......suppose if you really want to "extrapolate" one from the other it's not a far stretch. That being said, it would not dispute your defenition of 2 of the 3 possible causes for inaccurate results. My post was also referring to the independent labs that tend to generate most of their revenue from employer drug screens and not large medical facilities or hospitals.....and here again these are largely staffed by technicians with certifications, and not degreed chemists or scientist, who tend to be underpaid with bare minimum equipment....which could tie in all 3 of your routes to false positive/negative results.

My personal opinion is most false positives are due to your explanation of the fact that tests do not search for a specific drug and therefore may confuse anyhting from foods to an over the counter product for an illegal street substance.....and I guess my real problem with it is that in most cases....the test and the technician are unquestioned where as the patient or client is immediately suspect.

Ethereal

11-25-09, 05:35 PM

Thank you guys, you've provided me with some very useful information.

The urine sample wasn't even tested in a lab, but by some random nurse in the ward. I guess that if people working at labs can't get it right, the chances of things getting screwed up are even bigger when a drug test is performed in a hurry by nurses who seemed to have very little knowledge about this kind of thing, claiming that Ritalin, nor anything other than me doing meth, could have caused me to test positive for meth.

But, a blood sample, done by people in an actual lab, will distinguish between nasal spray and meth, right?

PedroDaGr8

11-25-09, 06:02 PM

OK, since I can't edit. It appears the most common metabolite for amphetamine is simply the p-hydroxylated, this means on the phenyl ring, directly across from where the ethyl group attaches, an OH group is added. For methylphenidate, it is the acid form.

PedroDaGr8

11-25-09, 06:22 PM

Thank you guys, you've provided me with some very useful information.

The urine sample wasn't even tested in a lab, but by some random nurse in the ward. I guess that if people working at labs can't get it right, the chances of things getting screwed up are even bigger when a drug test is performed in a hurry by nurses who seemed to have very little knowledge about this kind of thing, claiming that Ritalin, nor anything other than me doing meth, could have caused me to test positive for meth.

But, a blood sample, done by people in an actual lab, will distinguish between nasal spray and meth, right?

Yes, typically it should. Especially if they use a GCMS, staffed by a competent technician. Make sure they draw your blood now though, as meth only exists in the blood for 1-3 days.

As for the ritalin false positive. Not ALL immunoassay kits give a false positive for meth. Some do some don't.

secretADDmirer

11-30-09, 09:38 AM

Interesting thread, especially since a lot of us are on med(s) that will show up positive on a standard urine drug screen, i.e. amphetamines. In my line of work, I order a lot of urine drug screens, and I will share with you what I have learned. First, as many others have said, if you take your prescription bottle with you with an unaltered label on it, and show it to the collectors, there shouldn't be any problem if you test positive for it (at one of the places I worked, we would make a photo copy of the label, too). Second, most reputable labs run a preliminary test first using immunoassay. If there is a positive result, then they run a confirmatory test using gas chromatography/mass spectrometry, which is much more accurate. Also make sure a chain of custody is performed (it usually is) so the specimen is not out of your sight until it goes off to the lab. Lastly, 2 reputable labs are Ameritox and Advanced Toxicology Network (ATN). There are many others as well, but if a ward nurse collected it, there was no chain of custody performed, and confirmatory testing wasn't done by a reputable lab, I would demand another test with these regulations. Of note, advanced testing like that which is done by Ameritox and ATN can also show if you are taking the prescribed amount of the drugs you are on. Lastly (I mean it this time!), as PedroDaGr8 said, it is often the metabolites of these drugs that are positive, and infer what you have taken, so the toxicologist interpreting the test really needs to know about the breakdown and urinary excretion of the individual drug and its metabolites. Bottom line....if you have done nothing wrong, get educated about how these things work, how your test was run, etc. and then go teach them a thing or two!

Also, I just read an article that says ritalin/methylphenidate can cause false positive for amphetamine. http://www.erowid.org/chemicals/meth/meth_testing.shtml.